textproduct: Rapid City

KEY MESSAGES

- Active northwest flow through will persist through the week with rain and thunderstorm chances, best chances Thursday and Saturday.

- Cooler temperatures persist Wednesday before warming trend into the weekend.

DISCUSSION

(This Evening Through Tuesday) Issued at 1240 PM MDT Tue May 5 2026

A strong mid-level low is centered over northeastern Ontario with an upper trough axis stretching westward through the Northern Plains. Water vapor imagery shows a vort max pushing through the forecast area with active northwesterly flow upstream. Surface high pressure is centered over eastern Manitoba with brisk northwest surface flow across the Northern Plains. Cold air aloft + steep low-level lapse rates have resulted in a cellular cu field with virga/sprinkles possible across NW SD. Light showers possible across the SW third of the forecast area as the wave pivots through the region. Any precipitation amounts will be minimal.

Cooler weather persists tomorrow with generally dry conditions as subsidence overspreads the area through the day. Thermal ridge axis will push eastward Thursday into the weekend with temperatures warming through the weekend.

Active northwest flow persists through the week with another compact shortwave trough to arrive Thursday with rain showers and thunderstorms possible Thursday afternoon. Generally dry conditions Friday ahead of another wave that will bring additional shower and thunderstorm chances to the area Saturday.

AVIATION

(For the 18Z TAFS Through 18Z Wednesday) Issued At 1127 AM MDT Tue May 5 2026

Isolated showers may be possible this afternoon and evening over the Black Hills into southwestern SD, potential for low VFR to MVFR conditions in any showers. VFR conditions are expected through the period at both TAF sites.

UNR WATCHES/WARNINGS/ADVISORIES

SD...None. WY...None.